the thermostat can be set to 98-100 theoretically if the temps in your tub/cage are at the temp you want them to be. It really depends on a lot of factors including location of the cage, ambient temps outside the enclosure, etc.

I have my thermostat set at 93 to get the 91-92 hot spot i want in my cages in my current location, but before i moved i had to turn my thermostat up to 98 to get the same temps (i also have 2 thermometers attached to the heat tape at various places and a temp gun so im always checking temps).